On Mon, Mar 30, 2009 at 09:58:53AM +0000, feldmaus wrote: > feldmaus <feldmann_markus <at> gmx.de> writes: > > > Is there any example which corrects the dc offset ? > > So that we see, which commands are up to date. > > I think we have first to calculate the dc offset? > And the to adjust ? > > To calculate the dc offset we can use: > usrp_cal_dc_offset: > usage: usrp_cal_dc_offset [-v] [-w which_side] [-D decim] [-c ddc_freq] [-g > gain] > [-S fusb_block_size] [-N fusb_nblocks] > > And get for example this: > 1715545 : 172 2597454 : 260 > > Which is side A and which one is side B ? > The '-w' parameter doesn't change anything, so how to use this correctly ? > > To adjust the dc offset we can use: > set_dc_offset_cl_enable(self, int bits, int mask) > OR > set_adc_offset(self, int which_adc, int offset) > > Can somebody please explain the different between these both functions ? > Which one should we use to adjust the offset ? > > Regards Markus
A quick look at usrp_basic.h reveals: /*! * \brief Enable/disable automatic DC offset removal control loop in FPGA * * \param bits which control loops to enable * \param mask which \p bits to pay attention to * * If the corresponding bit is set, enable the automatic DC * offset correction control loop. * * <pre> * The 4 low bits are significant: * * ADC0 = (1 << 0) * ADC1 = (1 << 1) * ADC2 = (1 << 2) * ADC3 = (1 << 3) * </pre> * * By default the control loop is enabled on all ADC's. */ bool set_dc_offset_cl_enable(int bits, int mask); /*! * \brief Set ADC offset correction * \param which which ADC[0,3]: 0 = RX_A I, 1 = RX_A Q... * \param offset 16-bit value to subtract from raw ADC input. */ bool set_adc_offset (int which_adc, int offset); As it says above, "By default the control loop is enabled on all ADC's." You should leave it that way, with the possible exception of when using the LF RX daughterboard. Eric _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
